Donaldina Cameron (July 26, 1869 – January 4, 1968) was a New Zealand-born American Presbyterian missionary who was a pioneer in the fight against slavery in San Francisco's Chinatown, who helped more than 2,000 Chinese immigrant girls and women escape from forced prostitution or indentured servitude. She was known as "Fahn Quai," or the “White Devil” of Chinatown, as well as the "Angry Angel of Chinatown" and "Lo Mo."